Templates are used to automate the creation and deployment of hosts in Parallels RAS. A template is based on an existing virtual machine created with one of the hypervisors supported by Parallels RAS. Once a template is ready, it can be used to create clones (hosts) that will inherit all properties of the template. The resulting hosts can then be used to host published resources.
Read the following topics to learn how to create and use a template.
Virtual desktop templates are the essential part of the Parallels RAS VDI. They are used to create hosts for publishing of desktops, applications, documents, etc. The guest OS support is the same as for RAS Guest Agent (which must be installed in a VM). See Software requirements.
Hosts created from a Virtual desktop template normally serve a single user. They are managed entirely from within the RAS VDI, which includes such features as creating persistent VMs, managing VDI sessions, publishing resources from a specific Virtual desktop template, and others.
When you create a template, it is normally managed by a single Provider, which is the same provider to which the source virtual machine belongs. Clones are deployed from the template and run on the same Provider, which was used to create the template. Cloned hosts are usually stored on a centrally shared storage, such as Storage Area Network (SAN).
Beginning with Parallels RAS 18, admins have the ability to create a template and distribute it to multiple Microsoft Hyper-V hosts. As a result, the template configuration, as seen in the Parallels RAS Console, is shared among multiple Microsoft Hyper-V hosts, while each host has its own copy of the template residing on its local storage. This makes it possible to deploy clones not only to a centrally shared storage, but also to local disks of multiple independent Microsoft Hyper-V hosts. Scaling out is easily carried out by adding as many Microsoft Hyper-V hosts to the template distribution list as necessary.
Template distribution is configured on the Distribution page of the Create Parallels Template Wizard, which is described in the subsequent sections. If you are planning on using the template distribution functionality, please read the Prerequisites subsection below before running the wizard.
For more information about managing multi-provider distribution for a template, see also Managing multi-provider template distribution.
Template distribution is supported on a standalone Microsoft Hyper-V Server, 2016, 2019, and 2022.
All target Providers must have identical:
Provider type and subtype.
Folder path where hosts will reside.
Virtual switch name to which hosts are connected.
Hyper-V hosts must be domain-joined. The current implementation uses a full VM copy of the template to distribute the template to other hosts (local storage) via the Hyper-V Live Migration mechanism.
The Microsoft Hyper-V server hosting the source VM may also be used as a target host.
Always ensure that enough storage space is available prior to choosing target hosts to which the template will be distributed and on which clones will be created.
Hyper-V settings must have Kerberos authentication enabled and appropriate delegations configured in AD:
- Go to Hyper-V settings for the host machines and enable Live Migration using Kerberos.
- Go to Active Directory Users and Computers and for each Hyper-V host server enable delegation for "cifs" and "Microsoft Virtual System Migration Service" for all servers you want to migrate To and From.
To complete the tasks described in this section, the following requirements must be met:
For hypervisor-based hosts, make sure the hypervisor tools are installed and running in the host.
Make sure you know account credentials that will allow you to push install the agent software on a VM. If you run the Parallels RAS console using such credentials (e.g. a domain admin), you will not be asked to enter them during the agent installation. If you run the console using a different account, you'll be asked to enter credentials when you install the agent.
The guest OS (Windows) running in the VM must be configured to obtain an IP address from a DHCP server.
For users to access published resources in a host, the RDP port must be open locally or via Group Policy in Windows running in the VM. The default RDP port is 3389.
For RD Session Host templates, Network Discovery UDP port 137 must be enabled for a domain firewall profile in the guest OS. This can be done via domain group policies or manually in the guest OS.
Normally, you will push install the necessary agent software in a source VM right from the Parallels RAS console (as described later in this section). However, you can also install the software manually by running the Parallels RAS installer in Windows in the VM. When doing so, use the Custom installation option and select RAS Guest Agent to be installed in the source VM.
To begin creating a template:
In the RAS Console, navigate to Farm > <Site> > VDI.
Select the Templates tab in the right pane.
In the Tasks drop-down list, click Add (or click the "+" icon)
In the dialog that opens, select a host from which you would like to create a template and click OK.
The Create Parallels Template Wizard opens. Each wizard page is described below in the order they appear on the screen.
Verify that the Agent is installed and install it manually if needed as described in Step 1: Check and install the Agent. This step only appears if an on-premises Provider is used.
Configure the template as described in Step 2: Configure the template.
This step only appears if an on-premises Provider is used. It will not appear for Azure Virtual Desktop and cloud providers.
In this step, the wizard will check if the selected VM has the RAS Guest Agent installed. Wait for it to finish and then examine the Status field (closer to the bottom of the page). Depending on the result, do one of the following:
If the agent is installed, click Next to continue. You may stop reading here and jump to Step 2: Configure the template.
If the agent is not installed, you need to install it as described below.
To install the agent, first click the Customize Guest Agent deployment settings link and specify the options in the dialog that opens. None of the options are forced, so you can select or clear them depending on your needs. Note that depending on the template type, the options are different, as described below.
Add firewall rules: Automatically configure firewall rules in the host.
Allow remote desktop connections: Select to automatically configure remote desktop access in the VM.
Specify users or groups to be added to the Remote Desktop Users group: Select this option and then click the [+] icon to add specific users to the group.
Add firewall rules: Automatically configure firewall rules in the host.
Note: Network Discovery UDP port 137 must be enabled for a domain firewall profile in the guest OS as a separate step. This can be done via domain group policies or manually in the guest OS.
Install RDS role: Install the RDS role in the host.
Enable Desktop Experience: Enable the Desktop Experience feature in Windows.
Restart server if required: Restart the VM if required.
Specify users or groups to be added to the Remote Desktop Users group: Select this option and then click the [+] icon to add specific users to the group.
When done specifying the options, click OK to close the dialog.
Now click the Install button and follow the onscreen instructions to install the agent software.
Once done, verify that the agent is installed by looking at the Status field on the Check Agent wizard page. If so, continue to the next section that describes Step 2: Configure the template.
Once the agent is installed, and the Status field on the Check Agent wizard page confirms this, click Next. The VM will now be powered off (wait for the power off operation to finish). Once the VM is powered off, the template configuration Step begins.
The subsequent wizard pages are described in the sections that follow this one. Please note that many of the wizard pages inherit the information from Site default settings, but you can override it if needed. To specify your own settings, clear the Inherit default settings option. To see and edit default settings, click the Edit Defaults link. For more information, see Site defaults.
On the General page, specify the following options:
Template name: Choose and type a template name.
Clone method: Whether to create linked or full clones. A full clone is a complete copy of a template. As such, it occupies as much space on the physical hard drive as the source template and takes a significant time to create. A linked clone is a copy of a template made from a snapshot that shares virtual disk with the source template, therefore it takes much less space on the physical hard drive and it takes only a couple of minutes to create.
You should use full clones if your application and OS updates are too slow (full clones take longer to create, but they provide the best possible performance). Otherwise if your updates are fast enough, use linked clones as it takes much less time to create them.
(Microsoft Azure only) Availability set: Select a Microsoft Azure availability set.
Use the Distribution page to configure template distribution. Note that this page will only appear if the source VM is created with Microsoft Hyper-V or VMware vCenter.
To configure template distribution:
Select the Enable multi-provider template distribution option.
In the Available list, select one or more providers and click Add (or Add all to add all available providers). Note that only providers of the same type and subtype as the source VM are displayed in this list.
In the Number of providers for concurrent distribution field, specify the number of concurrent distribution operations. The template is distributed to target hosts using Hyper-V Live Migration, which first exports the virtual machine to a file and then moves it to the destination host. For each host in the Target list, a Live Migration operation must be performed. The number specified here dictates how many network copy operations should be started at the same time. The larger the number, the more network resources will be required. Note that virtual machine exports (the first step of Live Migration) are always done one VM at a time, so the number you specify here affect only the copy operations.
When done, click Next to proceed to the next wizard page.
For the description of this feature and requirements, please see Multi-provider template distribution.
Datastores are containers that store VMware virtual machines. By default, all hosts created from a template are stored in the same datastore as the template. You can choose to create hosts in several datastores, which will ensure that some hosts stay operational even if one datastore fails.
To select datastores for your hosts:
Select one of the following:
If you want to create all hosts in the datastore that contains the template, select Use the datastore containing the VM being converted to a template.
If you want to create hosts in several datastores, select Select additional datastores to use for template distribution.
(Optional) If you selected Select additional datastores to use for template distribution, select the datastores in the Datastores list.
Click Next.
The Advanced page has different properties for different types of Providers. The differences are described below.
Cluster Shared Volume (CSV), Network share: These two options appear if you are using Hyper-V Failover Cluster. They allow you to select a type of storage where hosts will be created. Select a desired option and then click the [...] button next to the edit field. Depending on the option selected, specify a Cluster Shared Volume or network folder. Note that a shared folder must be compatible with SMB 3.0. Please also note that the same credentials used to register Microsoft Hyper-V host as a Provider will be used to access the SMB file share for Hosts.
Please also read the important note below.
Folder: This option is available if you are using Hyper-V, VMware vCenter, or Nutanix AHV (AOS). It specifies a folder where hosts will be created.
Use a separate network interface for LAN access: This option is available if you are using any of the Hyper-V or VMware providers. Specifies the network interface that will be used by Connection Broker and Provider Agent. This is useful if a template has several network interfaces and you want to use a specific one for communication with Parallels RAS. If you select this option, you also need to specify the following:
Address: IP address of the network interface.
Subnet mask: Subnet mask of the IP address.
Resource pool: Specifies a VMware resource pool.
Physical Host: Available for VMware vCenter. Specifies a physical host where hosts will be created.
Enable hardware acceleration graphics licensing support: This option is available if you are using VMware vCenter or VMware ESXi. Select it to allow vGPU-enabled hosts to unregister their vGPU licenses from the license server on shutdown.
Resource group: Select an Azure resource group where the cloned VM will be created. Note that this must be a group to which you granted permissions to the Microsoft Entra ID app. For details, see Create a Microsoft Entra ID application.
Size: Select a VM size to be used for cloned VMs.
OS disk type: Select a disk type to be used for cloned VMs.
Use the Preparation page to select and configure an image preparation tool.
First, select whether you want to use RASprep or Sysprep. The advantages of using RASprep and the differences between the two tools are described below.
RASprep is the Parallels RAS tool for preparing Windows in a VM after cloning it from a base image. RASprep performs the following tasks during the initial startup of each new VM:
Creates a new computer account in Active Directory for each host.
Gives the host a new name.
Joins the host to the Active Directory domain.
Compared to Sysprep, RASprep works much faster because it modifies a lower number of configurable parameters and requires less reboots.
The following table lists the main differences between RASprep and Sysprep:
Delete local accounts
No
Yes
Generate new SIDs
No
Yes
Unjoin the parent host from the domain
No
Yes
Change computer name
Yes
Yes
Join the new instance to the domain
Yes
Yes
Language, regional settings, date and time customization
No
Yes
Number of reboots
1
2 (seal, mini-setup and domain joining)
After selecting the preparation tool, specify the following options:
Computer name: A name pattern that should be used to assign a computer name. For example, Windows10-RAS-%ID%.
Owner name: Owner name (optional).
Organization: Organization name (optional).
Administrative password: Local Windows administrator password.
Join domain: A domain name for the VM to join.
Administrator: Domain account.
Password: Domain account password.
Target OU: Full DN of an organizational unit. Click the [...] button to browse Active Directory and select an OU.
The Optimization page allows you to specify settings that will be used to optimize Windows running in hosts for best performance in a Parallels RAS environment. You can select Windows components, services, and other options that will be disabled, removed, or optimized to ensure a more efficient, streamlined, and improved delivery of virtual apps and desktops. For the complete description, please see Optimization.
After reading the Optimization section mentioned above, please also note the following VDI specifics:
Optimization is disabled by default when you create a new template. If you plan to enable it, you should make a backup (create a full clone) of the source host before doing so. You can also create a template with optimization disabled, then create a snapshot, and only then enable optimization. Making a backup is a good idea because once optimization settings are applied, they cannot be rolled back.
To enable optimization for an existing template, the template must be in maintenance. A template in the "Ready" state has the Optimization tab disabled.
When optimization is enabled or modified for an existing template and the template exits the maintenance mode, the administrator will be asked to recreate existing hosts, so that optimization settings are applied to them. Note that hosts must be recreated (now or later) to receive optimization settings.
When optimization is applied to a template, its status changes to Optimization in progress (among others). At this stage, you can select the template in the list and click Tasks > Stop optimization, which will cancel the operation.
On the License Keys page, specify the license key information that will be used to activate virtual machines created from this template.
First, select the license key management type that you are using in your organization (KMS or MAK). Parallels recommend to use KMS because MAK has limited activations.
Key Management Service (KMS): If you are using KMS, click the Finish button to save the template configuration information. Virtual machines that will be created from this template will look for KMS in DNS (at the end of the OS mini-setup and domain joining) and will be activated accordingly.
Multiple Activation Keys (MAK): If you are using MAK, do the following:
Click the Add button and type a valid key in the License key field.
In the Max. guests field, specify the key limit. The limit should be greater than or equal to the max guests in the template (which you set on the first page of the wizard)
Click OK.
On the Summary page, review the template summary information. You can click the Back button to correct some of the information if needed.
Finally, click Finish to create the template and close the wizard.
This section describes the host naming pattern that you specify on the Properties page of the template creation wizard.
Each time a new host is created, a name for it is generated automatically based on the pattern that you specify in the Host name field. The complete name format is as follows:
<prefix>%ID:N:S%<ending>
where:
<prefix> is an alphanumeric string that must begin with a letter (not a digit).
%ID:N:S% is a numeric pattern used to automatically generate a unique host ID. See the Numeric pattern subsection below.
<ending> is a free-form alphanumeric string.
The numeric pattern in the VM name has the following format:
%ID:N:S%
The elements in the pattern above are:
ID — Must be included as is.
N — The number of digits to use, including leading zeros. Use "0" if you don't want to insert leading zeros.
S — The starting number. This element is optional. If you don't include it, the number will start with 1.
%ID:3% — This pattern will generate 3 digit numbers with leading zeros, such as "001", "002", "003"...."998", "999".
%ID:3:200% — This example will generate 3 digit numbers starting from 200, such as "200", "201", "202"..."998", "999".
VDI-R1-%ID:3:100% — This is a complete name with an alphanumeric prefix and a numeric pattern. The resulting names will look like the following: "VDI-R1-100", "VDI-R1-101", etc.
When crating a name pattern, follow the rules listed below. If any of these rules are not observed, you will see an error message and will have to correct it:
The name must start with a letter. A digit is not allowed as the first character.
The alphanumeric part of a name can contain letters, digits, and a hyphen. No other characters are allowed.
The total length of the name must not exceed 15 characters.
The name can include just one numerical pattern (%ID:N:S%), which must be placed at the end or in the middle of the name.
The pattern that you specify is also validated against the value of the Maximum hosts field. If the pattern doesn't cover the maximum number of hosts, you will get an error and will have to correct it.
When you delete a host, the number that was assigned to it becomes unused. The next host that is created will be given this number, so there are no gaps in numbering.
The Parallels RAS Test Template Wizard is used to test the health of a template. The wizard allows you to see that all post-prep activities for a template complete correctly. This includes checking DHCP settings, DNS registration, correct VLAN, joining the AD domain, correct target OU, etc.
To open the wizard, right-click a template in the Parallels RAS console and choose Test. The test procedure consists of the following steps:
The template is switched temporarily to the "Test" mode designed specifically for this purpose. Please note that while the template is in this mode, all other operations are blocked until the test is finished and the template exits the test mode.
A host is cloned from it to be used for testing. The VM is kept on the server for the duration of the test and will be deleted afterwards.
A series of tests is then run on the host to test the template from which it was created.
Once the test is complete, a report is displayed on the screen showing the test results.
When the wizard starts:
The Welcome page opens. Read the info that it contains and click Next when ready.
The next page displays the list of individual tests that will be performed, including:
Check host Agent: This test tries to communicate with the RAS Guest Agent installed in the VM. If the agent responds, it means that the VM has been created and started successfully.
Check domain membership: Checks that the computer has joined the AD domain.
Check target OU: Checks that the RDP connection to the computer is possible with domain credentials.
Launch Parallels Client: This test launches Parallels Client and establishes a connection with the host.
While the test is running, the progress indicator is displayed on the screen. If needed, you can cancel the test at any time by clicking the Cancel button.
Once all tests are completed, you will see a page displaying the test results:
Success: If all tests complete successfully, the temporary host will be marked for deletion and the template will be switched back to the normal operation mode.
Failure: If one or more tests fail, you will see the corresponding info and will be able to download the log file by clicking the Download log file link. You will also have an option to switch the template to maintenance mode, which will prevent creating hosts from it until it is fixed.
Click Finish to close the wizard.
If you need to change the configuration of an existing template, select it in the Templates list and click Tasks > Properties. This opens the Template Properties dialog, which consists of tabs containing the same properties as the wizard pages described in Step 2: Configure the template.
After a template is created, Parallels RAS begins creating hosts from it, one virtual machine at a time. The number of VMs created at this time is determined by the Number of hosts deployed on the wizard completion property (all property names here and later refer to the Create Template Wizard described earlier).
The number of VMs available at any time will never go below the number specified in the Keep available buffer property. To comply with this rule, a new VM is automatically created when needed. At the same time, the total number of VMs will never exceed the number specified in the Maximum hosts property.
Please note that creating a new host from a template takes some time, especially when a template is configured to create full clones (linked clones are created much faster). If a host is in the middle of being created, and no other VMs are available, a user (or users) who need it will have to wait until the VM is ready.
If a host encounters a problem during the preparation stage, it will remain on the server in unusable state. You can identify such VMs by the Failed to create value in the Status column. Unless a VM like this is repaired or recreated, it will be automatically removed after the time period specified in the Auto remove hosts which failed preparation after field in Site defaults (Farm > <Site> > VDI > Desktops > Tasks > Site defaults). You can view the details of the failure to create a host by clicking on the Details link in the Status column or double-clicking the column. You can also choose Recreate or Delete from the same menu. For more information on how to recreate a host, please see the Template maintenance section.
A host is automatically deleted when it is not used longer than specified in the Delete unused hosts after field in template properties.
Hosts are created from a template automatically. In a situation when one or more additional hosts are required, you can add (create) them manually.
To add a host:
In the RAS Console, navigate to Farm > <Site> > VDI > Hosts.
Click the [+] icon at the top of the list.
In the Add Hosts dialog that opens, select a template from which to create a new host,
Specify the number of hosts to create. If the number you specify exceeds the Maximum hosts value set in the host pool properties (taking into account the number of VMs that already exist), you'll see a warning message and will need use a lower number or change the maximum host number on the Provisioning tab of the host pools properties.
Click OK to close the dialog.
After you click Apply in the RAS Console, the new hosts will appear in the list on the Desktop tab with the Status column saying "Cloning". Once the cloning is complete, the new hosts become available to users.
When you create VDI host pools, you can assign a template to a pool. This can be done when you create or modify a pool, or it can be done from the Templates tab.
To assign a template to a host pool:
On the Templates tab, select a template.
Click Tasks > Assign to pool. A wizard opens.
On the Versions page, select the template version that will be assigned to the host pool.
(Optional) On the Host pool page, select the host pools that you want to recreate on schedule and click the Next button. You will see a dialog that allows you to schedule recreation. Configure the schedule according to your needs and click Next.
Click Finish.
To remove a template from a host pool:
Select a template and click Tasks > Remove from pool.
A dialog opens listing all host pools to which this template is assigned.
Select the host pools to remove the template from and click OK.
Note that if a host pool has hosts created from the template that you are removing, they will be removed as well. A message is displayed where you need to confirm the removal.
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To verify that a template is functioning as intended, you can examine its status in the main template list in the RAS Console (the Status column). When a template is functioning properly, the Status column displays "Ready", which means that hosts can be created from it as needed. When a template is being created or when it's in maintenance, or when it's being removed, the status will change accordingly.
Note that one of the other columns in the table is Agent status, which is the status of the RAS Guest Agent installed in a template. Compared to servers in the RAS infrastructure (Connection Broker, Gateways, RD Session Hosts, etc), the agent status is not as important in a template as the template status. This is because a template is not a regular virtual machine and is not normally running, so checking the agent status in a stopped VM doesn't make much sense. This is why the agent status for a template in the RAS Console is usually Not Available, which is perfectly normal. The only situation when the Agent status displays a meaningful value is when the template is in Maintenance and running like a regular VM, in which case.the agent is also running an its status can be verified.
The tables below describe what the Status and Agent status columns will show for various template states or transitions.
Gray
Not available
Not available
When a provider is disabled or Provider Agent is disconnected or the template does not exist.
Gray
Not applied
Not applied
Awaiting admin to click Apply in the RAS Console after the wizard completion.
Orange
Creating
Not available
When using Azure Gallery as a source (no pre-created host available).
Orange
Agent installation
Not available then OK
Deploying the agent to a newly created or available VM to be used as a template.
Orange
Deployment in progress
Optimization pending
When the optimization is waiting to be applied. The admin can stop the optimization at this point.
Optimization in progress
When the optimization is in progress. The admin can still stop the optimization at this point.
OK then Not available
Internal procedure when converting a VM to a template. Once the conversion is completed, the template status changes to "Ready".
Red
Creation failed
Not available
A problem has occurred. For example, a quota hit or a resource creation issue in Azure. The admin can retry the action by clicking Tasks > Retry last action.
Red
Agent installation failed
Not available
Possible network issues, file share limitations, or an issue with admin rights. The admin can try Tasks > Retry last action.
Red
Deployment failed
The actual status (OK, Not available, etc.)
A problem has occurred. For example, a quota hit, storage space, or snapshot creation from provider issue. The admin can try Tasks > Retry last action.
FSLogix not available
FSLogix agent not found.
FSLogix not updated
FSLogix agent needs updating.
Green
Ready
The actual status (OK, Not available, etc.)
Template is ready.
Green
Cloning
The actual status (OK, Not available, etc.)
A host is being cloned from the template.
Orange
Needs update
Needs update
RAS Guest Agent needs updating.
Orange
Maintenance
The actual status (OK, Not verified, etc.)
Host used as the template is up and running,
Optimization pending
When the optimization is waiting to be applied. The admin can stop the optimization at this point.
Optimization in progress
When the optimization is in progress. The admin can still stop the optimization at this point.
Needs update
Host used as the template is up and running but RAS Guest Agent needs updating.
Gray
Marked for deletion
The actual status while the host used as the template is still running (OK, Not verified, etc.)
The template is in the process of being deleted.
For the description of the Multi-Provider Template Distribution feature, please see the Multi-provider template distribution section.
You can add or remove a Provider to/from a distribution list at any time using the template Properties dialog. To open the dialog, right-click a template on the VDI > Templates tab and choose Properties.
After you complete the Create Parallels Template Wizard and create a template, or when you add/remove a Provider to/from an existing template, you can monitor the template distribution status on the Templates tab. The status is displayed in the Distribution column and may have the following values:
Distributing — the distribution is in progress (the template is being distributed to target hosts).
OK — the template has been successfully distributed to all specified hosts.
Removing / Adding provider — A Provider is being added or removed.
Failed to distribute — indicates that an error has occurred during the distribution operation.
The Tasks > Distribution details menu on the Templates tab opens a dialog where you can view the current distribution State and Progress indicators for the Providers that use this template.
The Progress column displays the same values as the Distribution column in the main template list (see above).
The State column may display one of the following:
Ready — The Provider is ready.
Not available — The Provider is not responding.
Needs update — The template distribution operation may need to be performed again. You can click the Retry button to retry the template distribution operation for this host.
When a template leaves the maintenance mode, a prompt is usually displayed saying that "All hosts must be recreated because the template has been modified. Do you want to recreate them now?". If the administrator clicks Yes and the template uses multi-provider distribution, Parallels RAS verifies the status of each provider. If a Provider is not responding, a message is displayed, asking the administrator to check the provider status. You can bring the provider back online and try recreating the hosts again. If this cannot be done at this time, you can recreate the hosts later.
Hosts and other desktops are managed on the VDI > Desktops tab, where you can perform all of the standard desktop management operations from the Tasks menu. The operations include Recreate, Delete, Upgrade all Agents, Assign, Unassign, Show sessions, Start, Stop, Restart, Suspend, Reset, and others. The Restart operation (graceful) has a 10 min timeout. If not completed during this time, the Reset operation (forced) will be used.
By default, the Desktops tab displays all of the desktop available in the Farm (you may need to scroll the list to see all available desktops). To see just the hosts that belong to a specific template, select a template in the Templates tab and click Tasks > Show hosts. This will switch you to the Desktops tab where the list will be automatically filtered to include only the VMs that belong to the selected template.
For more information, see Managing hosts.